Information recorded medium, device for reading the information, information recorded medium transfer foil, and method for producing information recorded medium

An information reader that reads information recorded on an information recording medium comprising a base member, a resin layer having a surface having a pattern region provided with a three-dimensional diffraction grating or a holographic pattern, and a ferromagnetic thin film formed on the resin layer and having a magnetic characteristic subject to the diffraction grating or the holographic pattern of the pattern region, said information reader comprising:

• an exciting means for ac-exciting the pattern region of the information recording medium in a predetermined direction;
• a magnetic head means for scanning the pattern region along the predetermined direction and reading a variation of magnetic flux provided by the information recording medium excited by ac-excitation;
• and
• a driving means for driving the information recording medium relative to the magnetic head means or the magnetic head means relative to the information recording medium to move the information recording medium or the magnetic head continuously or intermittently at a moving speed far lower than a scanning speed of the magnetic head means in a feed direction perpendicular to the scanning direction in which the magnetic head means moves relative to the information recording medium for scanning.

A counterfeiting preventing sheet comprising:

• an information recording medium comprising a base member, a resin layer having a pattern region provided with a three-dimensional diffraction grating or a holographic pattern, and a ferromagnetic thin film formed on the resin layer and having a magnetic characteristic in accordance with the diffraction grating or the holographic pattern of the pattern region;
• and
• a backing sheet in which the information recording medium is embedded;
• wherein the backing sheet has open parts arranged at intervals to expose parts of the information recording medium therein, and covering parts extending between the open parts and covering parts of the information recording medium.

An information recording medium transfer foil comprising:

• a base member;
• a resin layer formed on the base member and having a pattern region provided with a three-dimensional diffraction grating or a holographic pattern;
• a ferromagnetic thin film formed on the resin layer;
• and
• a heat-sealable layer or an adhesive layer formed on the ferromagnetic thin film;
• wherein the ferromagnetic thin film has a magnetic characteristic in accordance with the diffraction grating or the holographic pattern of the pattern region.